Publication Date:
2021-05-17
Description:
The Kuril Island arc extending for about 1,200 km from Kamchatka Peninsula to Hokkaido
Island is a typical active subduction zone with 40 historically active subaerial volcanoes, some of which
are persistently degassing. Seven Kurilian volcanoes (Ebeko, Sinarka, Kuntomintar, Chirinkotan, Pallas, Berg,
and Kudryavy) on six islands (Paramushir, Shiashkotan, Chirinkotan, Ketoy, Urup, and Iturup) emit into the
atmosphere〉90% of the total fumarolic gas of the arc. During the field campaigns in 2015–2017 direct
sampling of fumaroles, MultiGas measurements of the fumarolic plumes and DOAS remote determinations
of the SO2 flux were conducted on these volcanoes. Maximal temperatures of the fumaroles in 2015–2016
were 5108C (Ebeko), 4408C (Sinarka), 2608C (Kuntomintar), 7208C (Pallas), and 8208C (Kudryavy). The total
SO2 flux (in metric tons per day) from fumarolic fields of the studied volcanoes was measured as
1,8006300 t/d, and the CO2 flux is estimated as 1,2506400 t/d. Geochemical characteristics of the sampled
gases include dD and d18O of fumarolic condensates, d13C of CO2, d34S of the total sulfur, ratios
3He/4He and 40Ar/36Ar, concentrations of the major gas species, and trace elements in the volcanic gas condensates.
The mole ratios C/S are generally 〈1. All volcanoes of the arc, except the southernmost Mendeleev
and Golovnin volcanoes on Kunashir Island, emit gases with 3He/4He values of 〉7RA (where RA is the
atmospheric 3He/4He). The highest 3He/4He ratios of 8.3RA were measured in fumaroles of the Pallas volcano
(Ketoy Island) in the middle of the arc.
Description:
Published
Description:
1859-1880
Description:
4V. Processi pre-eruttivi
Description:
JCR Journal
Repository Name:
Istituto Nazionale di Geofisica e Vulcanologia (INGV)
Type:
article
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